Upload
others
View
7
Download
0
Embed Size (px)
Citation preview
2.2 : Human Blood Constituents of Blood in Human Beings
• Normal adult has about 5 – 6 litres of blood • Blood : A type of fluid that is made up of liquid
and solid • Liquid component : – Is called plasma – 55%
• Solid component : – Red blood cells – White blood cells – Platelets – 45%
Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Constituents of Blood in Human Beings
• Both components can be separated from a blood sample by using centrifuge
• When blood is rotated in a spinning centrifuge, it is separated into – blood cells (lower
section) – Plasma fluid
(upper section) Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Constituents of Blood – PLASMA
• Light yellow • Contains 92%
water and 8% dissolved substances such as – Digested food
(glucose, amino acid, fatty acid)
– Excretory products (CO2, urea)
– Proteins (albumin, antibody)
– Vitamins & minerals Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Constituents of Blood – PLASMA
• Functions – Transport
digested food to tissues
– Transport excretory products from tissues
– Distribute heat throughout the body to maintain body temperature at 37°C
Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Constituents of Blood – RED BLOOD CELLS
• Are called as erythrocytes – found most in blood
• Haemoglobin – red pigment which contains iron & protein
• Biconcave disc-shaped
• Thick on the edge & thin in the centre – able to squeeze in the small capillary
Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Constituents of Blood – RED BLOOD CELLS
• No nucleus – increases the surface area to transport MORE 02
• Produced in bone marrow with lifespan up to 120 days
• Old RBC is destroyed in the liver and lymph
• Anaemia : lack of RBC
Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Constituents of Blood – WHITE BLOOD CELLS
• Is called as leucocytes
• Made up of membrane, cytoplasm & nucleus
• Bigger size than RBC • Colourless with
indefinite shape to penetrate the blood capillary/body cells
• Defends the body against microbes
Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Constituents of Blood – WHITE BLOOD CELLS
TYPES OF WBC • Lymphocytes – To produce
antibodies that are able to destroy pathogens
• Phagocytes - To ingest the
pathogens before destroying them.
Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood
Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Constituents of Blood – WHITE BLOOD CELLS
• Produced in the bone marrow & lymph nodes
• Lifespan : A few days to many months
• Old WBC is destroyed in blood circulation – excrete together with urine & faeces
• Lack WBC – weak immune system
• Leukaemia : A type of cancer with excess WBC – patients get infected easily & can be fatal Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Constituents of Blood – PLATELETS
• Known as thrombocytes
• Not complete cells – fragments of cytoplasm from bone marrow
• No nucleus, colourless & spherical
• Lifespan : 10 days • Old platelets are
destroyed in blood circulation
Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Constituents of Blood – PLATELETS
• Helps in blood clotting to prevent – blood loss – Microbes entering
the body through injured skin
• Haemophilia : genetic disorder caused by insufiicient platelets – continuous
bleeding – Prevent clotting – Fatal Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Constituents of Blood – PLATELETS
Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Blood Group
• Four groups :- • A, B, O, AB
• Knowledge of blood groups is important in the blood transfusion
• Transfusion : Process of blood transferring
• When blood of two incompatible groups is mixed, RBC of the donor & recipient will clump together – AGGLUTINATION : reduces surface area for gas diffusion & leads to fatal
Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Blood Group
• Blood group O : • Aka universal
donor – can donate to any blood group
• Can only receive from group O
• Blood group AB : • Aka universal
recipient – can receive blood from any blood group
• Can only donate to group AB
Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Compatibility of Blood Groups
Prepared by Ms Sue Soh Ya Lee
2.2 : Human Blood Blood Donation
• There are many reasons why blood transfusion is needed
• Who can donate blood? • Donated blood is
screened to ensure free of microbes : parasites, hepatitis virus or HIV
• Screened blood is divided into its components
• RBC : stored in fridge & last about 40 days
• Plasma : frozen & last for about 1 year
Prepared by Ms Sue Soh Ya Lee